Which DJ Shadow's song contains lyrics "whatcha gonna do now - now - now?" it's either at the beginning or the end of this track
The song that contains the lyrics 'whatcha gonna do now' was sung by Tommy Collins. That is the tile of the song and the sing also ends with those words. You can find the lyrics on http://www.lyricsfreak.com/t/tommy+collins/whatcha+gonna+do+now_20463757.html. However, there are other similar songs that have the same lyrics such as 'whatcha gonna do now' by Buck Owens.